Abstract: Maillard reaction products （MRPs） were prepared by the reaction of porcine bone protein hydrolysates （PBPH） and glucose or xylose. MRPs were isolated to fractions with different molecular weights （＜1， 1-5， 5-10，>10 ku） by ultrafiltration. The antioxidative activity of the fractions was determined in vitro， respectively. The results showed that all fractions exhibited antioxidative activity， especially the fractions （MW>10 ku） had the highest DPPH radical scavenging ability， reducing power and Fe2+ chelating activity. It revealed that antioxidative activity of MRPs with high molecular weight were more efficient. The differences of radical scavenging ability， reducing power and Fe2+ chelating activity between MRPs derived from glucose and xylose were not significant （P＞005）， indicating that sugar structure showed no effect on antioxidative activity of MRPs prepared in this study.

Key words: porcine bone protein hydrolysates, Maillard reaction products, antioxidative activity